Browsing by Author "Yoko, Matthew Jonathan"

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    Conjugate heat transfer analysis of an impingement/effusion cooled combustor liner
    (Stellenbosch : Stellenbosch University, 2020-03) Yoko, Matthew Jonathan; Van der Spuy, S. J.; Sethi, V.; Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering.
    ENGLISH ABSTRACT: The design of gas turbine combustors is a costly, iterative process which is heavily reliant on empirical modelling. To facilitate the design of novel low emissions combustors, a multi-fidelity design process has been proposed. In this process, physics-based low order models are built; calibrated by high fidelity simulations and then used in multi-objective optimisation studies. The current work contributes to this process by providing a method of performing high fidelity multiphysics simulations of an impingement/effusion cooling scheme for a combustor liner wall. A conjugate heat transfer CFD model was used to capture details of the combusting flow field and its interaction with the liner wall. While this method has been successfully applied to pure effusion cooling, it had not yet been used to study impingement/effusion cooling in a representative combustor. Further to this, the impact of radiation modelling was investigated as this had not been considered in previous work. The method was validated against a simple experimental case study before being applied to a representative gas turbine combustor. It was shown that this method is capable of predicting impingement/effusion cooling performance to within 1% for a simple case. The combustor case study revealed a number of 3D effects which had not been captured by the low order model, most notably a strong interaction between the swirling flame and the cooling film. This informed recommendations for improvements to the low order model. It was further shown that radiative heat flux contributed up to 33% of the total flux, justifying the inclusion of radiation modelling in these studies. Finally, a strong sensitivity to the level of soot fouling was shown, with a potential doubling of radiative heat flux as a result. Further work is required to estimate the level of soot fouling on the liner walls, allowing the liner emissivity distribution to be more reliably constructed.